This is a follow up study to evaluate the neurodevelopmental status of children with pulmonary hypertension at birth who were enrolled in the randomized trial of inhaled nitric oxide. Study staff will schedule a follow-up visit with the parent. The visit will take approximately 2-3 hours. During the visit, the infant will have a neurological, developmental, and physical exam performed by a pediatrician. Parents will be asked questions about their child's developmental, demographic, and medical history, and behavior.